Heat insulating panel and heat insulating structure

ABSTRACT

A heat insulation panel includes a plate-shaped vacuum heat-insulation material embedded in a board-shaped resin foam. When the heat insulation panel is brought into abutment with another heat insulation panel of same dimensions and structure at proximal edges thereof, the vacuum heat-insulation materials in the respective heat insulation panels are in a relationship that the vacuum heat-insulation materials overlap with each other at their proximal end portions as viewed in a thickness direction of the heat insulation panels. The heat insulation panel is economical and is excellent in heat insulating properties, handling, installation and the like. A heat insulation structure making use of a plurality of such heat insulation panels is also provided.

This application is a U.S. national phase filing under 35 U.S.C. §371 ofPCT Application No. PCT/JP2008/071498, filed Nov. 27, 2008, which claimspriority to Japanese Patent Application No. 2007-306419 filed on Nov.27, 2007, the entire disclosures of which being incorporated herein, andto which all priority rights are hereby claimed.

TECHNICAL FIELD

This invention relates to a heat insulation panel and a heat insulationstructure, and specifically to a heat insulation panel, which iseconomical and is excellent in heat insulating properties, handling,installation and the like, and also to a heat insulation structuremaking use of a plurality of such heat insulation panels.

BACKGROUND ART

Diversified heat insulation materials have been used to date in variouswalls, ceilings, floors and roofs of a wide range of buildings toheighten air-conditioning effects. As these heat insulation materials,resin foams such as polyethylene foams and polyurethane foams are widelyused from the standpoints of moldability and cost. A variety of heatinsulation materials are also used in various cool boxes, insulatedtrucks or vans, refrigerators, vehicles and the like to improve thermalinsulation effects or air-conditioning effects. As it is essential forthese heat insulation materials to have a small thickness, so-calledvacuum heat-insulation materials are used. To further improve heatinsulating effects, composite heat insulation materials with vacuumheat-insulation materials encapsulated therein are also used (PatentDocument 1).

Patent Document 1: JP-A-2004-278632 DISCLOSURE OF THE INVENTION Problemto be Solved by the Invention

As illustrated in FIG. 5, the heat insulation panel disclosed in PatentDocument 1 is composed of a resin foam 1 and a vacuum heat-insulationmaterial 2 embedded therein. When many of such heat insulation panelsare installed in abutment with each other for heat insulation purposes,heat insulating properties are not considered to be sufficient in thatthe vacuum heat-insulation material 2 does not exist at a part indicatedby arrows in FIG. 6 and thermal radiation cannot be satisfactorilyshielded there, although a synergism of the effects of the vacuumheat-insulation materials 2 and the effects of the resin foams 1 can beexpected.

It may also be contemplated to lap-joint vacuum heat-insulationmaterials together. It is, however, not easy to manufacture lap-jointvacuum heat-insulation materials. A panel may be assembled by jointingvacuum heat-insulation materials together. However, such a panel mayitself be unable to retain sufficient rigidity unless adhesion issufficient at the joints.

Aspects of the present invention are, therefore, to provide a heatinsulation panel, which is economical and is excellent in heatinsulating properties, handling, installation and the like, and also aheat insulation structure making use of a plurality of such heatinsulation panels.

Means for Solving the Problem

The above-described aspects can be achieved by the present invention tobe described hereinafter. Described specifically, the present inventionprovides a heat insulation panel with a plate-shaped vacuumheat-insulation material embedded in a board-shaped resin foam, wherein,when the heat insulation panel is brought into abutment with anotherheat insulation panel of same dimensions and structure at proximal edgesthereof, the vacuum heat-insulation materials in the respective heatinsulation panels are in a relationship that the vacuum heat-insulationmaterials overlap with each other at proximal end portions thereof asviewed in a thickness direction of the heat insulation panels.

In the present invention, it is preferred that an overlap width of thevacuum heat-insulation materials themselves, which are in themutually-overlapping relationship, is from 5 to 80 mm as viewed in awidth direction of the heat insulation panels; that the board-shapedresin foam is composed of two rectangular resin foams of same dimensionsoverlapping one over the other and changed in position relative to eachother in a length direction and/or width direction thereof, and the tworectangular resin foams are provided with plate-shaped vacuumheat-insulation materials encapsulated therein, respectively; or thatthe board-shaped resin foam is composed of two rectangular resin foamsof different lengths and/or widths overlapping one over the other withcenterlines thereof coincided with each other, and larger one of the tworectangular resin foams is provided with the plate-shaped vacuumheat-insulation material encapsulated therein.

The present invention also provides a heat insulation structurecomprising a plurality of heat insulation panels according to thepresent invention, wherein the heat insulation panels are arranged inabutment with each other at proximal edges thereof such thatplate-shaped vacuum heat-insulation materials thereof overlap with eachother at proximal end portions thereof as viewed in a thicknessdirection of the heat insulation panels.

ADVANTAGEOUS EFFECTS OF THE INVENTION

According to the present invention, it is possible to provide a heatinsulation panel, which is economical and is excellent in heatinsulating properties, handling, installation and the like, and also aheat insulation structure making use of a plurality of such heatinsulation panels.

BEST MODE FOR CARRYING OUT THE INVENTION

Based on preferred embodiments shown in drawings, the present inventionwill next be described in further detail.

As shown in FIG. 1, a heat insulation panel 10 according to oneembodiment of the present invention includes a board-shaped resin foamA, which is composed of two rectangular resin foams 1,1 of samedimensions overlapping one over the other and changed in positionrelative to each other in a width direction (or a length direction)thereof, and the two rectangular resin foams are provided with vacuumheat-insulation materials 2,2 encapsulated therein, respectively. Theresin foams 1,1 and the vacuum heat-insulation materials 2,2 are in arelationship that, when two of such heat insulation panels (one of whichis indicated by dotted lines) are brought into abutment with each otherat proximal edges thereof, the lower vacuum heat-insulation material 2in one of the heat insulation panels and an upper vacuum heat-insulationmaterial 2′ in the adjacent heat-insulation panel (which is indicated bythe dotted lines) overlap one over the other at proximal end portionsα,α′ thereof as viewed in a thickness direction of the heat insulationpanels.

In the heat insulation panel 10 shown in FIG. 1, the panel-shaped resinfoam A is composed of the two rectangular resin foams 1,1 of the samedimensions overlapping one over the other and changed in positionrelative to each other in the width direction thereof. As analternative, the two resin foams 1,1 may be changed in position relativeto each other in the length direction thereof (not illustrated). Asdepicted in FIG. 2, a panel-shaped resin foam A may also be composed oftwo rectangular resin foams 1,1 of same dimensions overlapping one overthe other and changed in position relative to each other in a widthdirection and length direction thereof. There are depicted a side viewof the heat insulation panel according to this modification in FIG. 2 a,its top plan view in FIG. 2 b, its cross-sectional view taken along lineA-A′ of FIG. 2 a in FIG. 2 c, and its cross-sectional view taken alongline B-B′ of FIG. 2 b in FIG. 2 d. The remaining construction of theheat insulation panel according to this modification is the same as thatof the embodiment shown in FIG. 1.

As illustrated in FIG. 3, a heat insulation panel 10 according toanother embodiment of the present invention includes a panel-shapedresin foam A, which is composed of two rectangular resin foams 1,1 ofdifferent widths overlapping one over the other with centerlines thereofcoincided with each other, and larger one of the two rectangular resinfoams 1,1 is provided with a vacuum heat-insulation material 2encapsulated therein. Similar to the embodiment shown in FIG. 1, theresin foams 1,1 and the vacuum heat-insulation material 2 are in arelationship that, when two of such heat insulation panels 1,1 (one ofwhich is indicated by dotted lines) are brought into abutment with eachother at proximal edges thereof, the vacuum heat-insulation materials2,2 in the respective heat insulation panels overlap one over the otherat proximal end portions α,α′ thereof as viewed in a thickness directionof the heat insulation panels.

In the heat insulation panel 10 illustrated in FIG. 3, the panel-shapedresin foam A is composed of the two rectangular resin foams 1,1 ofdifferent widths overlapping one over the other with the centerlinesthereof coincided with each other. As shown in FIG. 4, however, theresin foam 1 located on the lower side as viewed in the drawing may besmaller in both width and length than the resin foam located on theupper side. There are shown a side view of the heat insulation panel 10according to this modification in FIG. 4 a, its top plan view in FIG. 4b, its cross-sectional view taken along line A-A′ of FIG. 4 a in FIG. 4c, and its cross-sectional view taken along line B-B′ of FIG. 4 b inFIG. 4 d. The remaining construction of the heat insulation panelaccording to this modification is the same as that of the embodimentillustrated in FIG. 3.

When a plurality of such heat insulation panels 10 according to thepresent invention are installed in abutment with each other on a wallsurface or the like for heat insulation purposes as shown in FIG. 1 orFIG. 3, the vacuum heat-insulation materials in the adjacent heatinsulation panels overlap one over the other at proximal end portionsthereof as viewed in a thickness direction of the heat insulationpanels. Therefore, the heat insulation panels can reflect thermalradiation from everywhere the interior or exterior of a room or thelike, and are provided with pronouncedly-improved heat insulatingproperties.

The above-described resin foams may each be a foam of any resin, with apolyurethane-based foam being preferred from the standpoint ofmoldability. A polyurethane foam can be obtained in a desired shape bymixing a polyol component, a polyisocyanate component and a foamingagent, pouring the mixture into a mold cavity of the desired shape, andthen subjecting the mixture to expansion molding. From the standpoint ofa balance between heat insulating properties and strength, the expansionratio of the foam may preferably be from 5 to 50 times or so.

Each vacuum heat-insulation material for use in the present invention isa heat insulation material that a core material formed of laminatedglass fibers is encapsulated in a barrier envelope and the barrierenvelope is depressurized. Such a vacuum heat-insulation material itselfis known, and any known vacuum heat-insulation material can be used inthe present invention. A preferred vacuum heat insulation material mayinclude, as an envelope, at least one metallized layer as in analuminum-metallized polyethylene film. The inclusion of such ametallized layer can provide improved heat insulating properties (heatshielding properties) especially in summer. The vacuum heat-insulationmaterial may generally be from 3 to 20 mm or so in thickness and from190 to 1,300 mm×190 to 1,300 mm or so in size.

No particular limitation is imposed on a process for the formation ofthe above-described heat insulation panels according to the presentinvention, each of which is composed of the resin foams and the vacuumheat-insulation material or materials. As a preferred example, however,the following process can be mentioned. In the case of the embodimentshown in FIG. 1, a heat insulation panel member 20 of a constructiondepicted in FIG. 5 (which corresponds to an upper half above a thickdashed line in FIG. 1) is molded by pouring a polyurethane formulationinto a mold cavity of a predetermined shape with a vacuumheat-insulation material 2 held at a predetermined position in the moldcavity, and then subjecting the polyurethane formulation to expansionmolding. Two of such heat insulation panels molded as described aboveare then integrated together with their positions shifted relative toeach other in a width direction (and/or a length direction) to obtainthe heat insulation panel 10 shown in FIG. 1.

On the other hand, the heat insulation panel 10 illustrated in FIG. 3can be obtained by molding an unillustrated resin foam (whichcorresponds to a lower half below a thick dashed line in FIG. 3), whichis similar to the heat insulation panel member 20 depicted in FIG. 5 butdoes not include the encapsulated vacuum heat-insulation material 2 andis smaller in width (and/or length) than the heat insulation panelmember 20, and integrating the resin foam with the heat insulation panelmember 20 with their centerlines coincided with each other.

A description will next be made about the sizes of the heat insulationpanels 10 according to the present invention. In the heat insulationpanel 10 shown in FIG. 1, its length (L) may be from 200 to 2,000 mm orso, with from 900 to 1,800 mm being more preferred. A length (L) smallerthan 200 mm results in inferior thermal performance, while a length (L)greater than 2,000 mm leads to deteriorations in shipping ease andinstallation. Lengths (L) outside the above-described range aretherefore not preferred. For the same reasons as mentioned above withrespect to the length (L), its width (W) may be preferably from 200 mmor greater, more preferably from 400 to 1,500 mm or so.

Its thickness (H) may be from 30 to 100 mm or so, and its indentation(a) may be from 10 to 110 mm or so, with from 40 to 90 mm beingpreferred. The width (b) of the upper or lower half in the whole heatinsulation panel may be from 350 to 1,450 mm or so, and the thickness(c) of the upper or lower half may be from 15 to 50 mm or so. Eachvacuum heat-insulation material 2 has a length similar to theabove-described length (L) of the foam, and its thickness and size aresimilar to those described above. The distance (d) between an end edgeof each vacuum heat-insulation material 2 and a proximal end edge of itscorresponding resin foam 1 may be from 3 to 20 mm or so.

In the heat insulation panel illustrated in FIG. 3, on the other hand,the dimensions of the upper half above the thick dashed line in thefigure may be similar to those of the above-described heat insulationpanel member 20, the thickness of the lower half below the thick dashedline may be similar to the above-described thickness (c), and theindentation (a) may be similar to the above-described indentation (a).

The overlap widths α′,α of the upper and lower, vacuum heat-insulationmaterials 2 may each be 5 mm or greater, preferably from 30 to 80 mm. Anoverlap width smaller than 5 mm leads not only to difficulty in holdingpanels in abutment with each other but also to inferior thermalperformance. An overlap width greater than 80 mm, on the other hand,results in a reduction in the strength of the edge portion of eachpanel. The inter-layer spacing (e) between the vacuum heat-insulationmaterials may preferably be 6 mm or greater for excellent heatinsulating properties, with from 20 to 50 mm being more preferred.

Such heat insulation panels according to the present invention asdescribed above are useful as heat insulation materials for variouswalls, ceilings, floors and roofs in a wide range of buildings and alsoas heat insulation materials for various cool boxes, insulated trucks orvans, refrigerators, vehicles and the like, and have excellent heatinsulating properties and installation convenience.

EXAMPLES

Based on examples and comparative examples, the present invention willnext be described specifically.

Examples 1-6

Heat insulation panels, each of which had the construction of theembodiment shown in FIG. 1 and included two vacuum heat-insulationmaterials encapsulated in board-shaped resin foams, respectively, wereformed as Examples 1-6 with the overlap width α of each vacuumheat-insulation material varied to 2.5 mm, 5 mm, 10 mm, 30 mm, 50 mm and90 mm, respectively. Detailed conditions and measurement results ofthermal performance (heat transmission coefficient) are presented inTable 1-1.

Examples 7-12

Heat insulation panels, each of which had the construction of theembodiment shown in FIG. 3 and included one vacuum heat-insulationmaterial encapsulated in a board-shaped resin foam, were formed asExamples 7-12 with the overlap width α of the vacuum heat-insulationmaterial varied to 2.5 mm, 5 mm, 10 mm, 30 mm, 50 mm and 90 mm,respectively. Detailed conditions and measurement results of thermalperformance (heat transmission coefficient) are presented in Table 1-2.

Comparative Examples 1 & 2

As examples of abutment of heat insulation panels, which are similar tothat shown in FIG. 5, without overlapping of vacuum heat-insulationmaterials, a board-shaped foam with two vacuum heat-insulation materialsencapsulated therein was provided as Comparative Example 1, and aboard-shaped foam with one vacuum heat-insulation material encapsulatedtherein was provided as Comparative Example 2. Detailed conditions andmeasurement results of thermal performance (heat transmissioncoefficient) are presented in Table 1-3.

Measurement Method

In each of the above-described examples and comparative examples, two ofthe heat insulation panels were brought into abutment with each other,the temperature was controlled at a high temperature (20° C.) on oneside and at a low temperature (0° C.) on the other side. The heat flowrate was evaluated by heat flowmeters on the low-temperature surfaces ofan abutting portion (50×50 mm) and a central portion (50×50 mm) of oneof the heat insulation panels to determine the heat transmissioncoefficients. The evaluation results are presented in Tables 1-1 to 1-3.

TABLE 1-1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Panel width W (mm) 450 450450 450 450 450 Panel thickness H (mm) 32 32 32 32 32 32 Thickness ofurethane surface layer (skin 5 5 5 5 5 5 layer) (mm) Urethane thicknessd at opposite edge 5 5 5 5 5 5 portions (mm) Number of vacuumheat-insulation materials 2 2 2 2 2 2 Thickness of vacuumheat-insulation 7 7 7 7 7 7 materials (mm) Inter-layer spacing e ofvacuum 8 8 8 8 8 8 heat-insulation materials (mm) Overlap width a ofpanels (mm) 12.5 15 20 40 60 100 Overlap width α of vacuumheat-insulation 2.5 5 10 30 50 90 materials (mm) Heat transmissioncoefficient at panel edge 0.72 0.48 0.48 0.31 0.26 0.25 portion (W/m²K)Heat transmission coefficient at panel 0.13 0.13 0.13 0.13 0.13 0.13central portion (W/m²K)

TABLE 1-2 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 Ex. 12 Panel width W (mm) 450 450  450  450  450  450  Panel thickness H (mm) 32  32  32  32  32  32 Thickness of urethane surface layer (skin 5 5 5 5 5 5 layer) (mm)Urethane thickness d at opposite edge 5 5 5 5 5 5 portions (mm) Numberof vacuum heat-insulation materials 1 1 1 1 1 1 Thickness of vacuumheat-insulation 7 7 7 7 7 7 materials (mm) Inter-layer spacing e ofvacuum  8*  8*  8*  8*  8*  8* heat-insulation materials (mm) Overlapwidth a of panels (mm)  12.5 15  20  40  60  100  Overlap width α ofvacuum heat-insulation   2.5 5 10  30  50  90  materials (mm) Heattransmission coefficient at panel edge   0.72   0.48   0.48   0.31  0.26   0.25 portion (W/m²K) Heat transmission coefficient at panel  0.21   0.21   0.21   0.21   0.21   0.21 central portion (W/m²K)*Inter-layer spacing of vacuum heat-insulation materials encapsulated intwo heat insulation panels, respectively.

TABLE 1-3 Comp. Comp. Ex. 1 Ex. 2 Panel width W (mm) 450 450 Panelthickness H (mm) 32 32 Thickness of urethane surface layer (skin 5 5layer) (mm) Urethane thickness d at opposite edge 5 5 portions (mm)Number of vacuum heat-insulation materials 2 1 Thickness of vacuumheat-insulation 7 7 materials (mm) Inter-layer spacing e of vacuum 8 0heat-insulation materials (mm) Overlap width a of panels (mm) 0 0Overlap width α of vacuum heat-insulation 0 0 materials (mm) Heattransmission coefficient at panel edge 4.17 4.17 portion (W/m²K) Heattransmission coefficient at panel 0.13 0.21 central portion (W/m²K)

INDUSTRIAL APPLICABILITY

According to the present invention as described above, it is possible toprovide a heat insulation panel, which is economical and is excellent inheat insulating properties, handling, installation and the like, andalso a heat insulation structure making use of a plurality of such heatinsulation panels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a heat insulation panelaccording to the present invention.

FIG. 2 is a view illustrating a modification of FIG. 1.

FIG. 3 is a perspective view illustrating another heat insulation panelaccording to the present invention.

FIG. 4 is a view illustrating a modification of FIG. 3.

FIG. 5 is a view illustrating a conventional heat insulation panel.

FIG. 6 is a view illustrating conventional heat insulation panels.

LEGEND

-   A(1,1′) Resin foam-   2,2′ Vacuum heat-insulation material-   10 Heat insulation panel-   20 Heat insulation panel member

1. A heat insulation panel with a plate-shaped vacuum heat-insulationmaterial embedded in a board-shaped resin foam, wherein, when the heatinsulation panel is brought into abutment with another heat insulationpanel of same dimensions and structure at proximal edges thereof, thevacuum heat-insulation materials in the respective heat insulationpanels are in a relationship that the vacuum heat-insulation materialsoverlap with each other at proximal end portions thereof as viewed in athickness direction of the heat insulation panels.
 2. The heatinsulation panel according to claim 1, wherein an overlap width of thevacuum heat-insulation materials themselves, which are in themutually-overlapping relationship, is from 5 to 80 mm as viewed in awidth direction of the heat insulation panels.
 3. The heat insulationpanel according to claim 1, wherein the board-shaped resin foam iscomposed of two rectangular resin foams of same dimensions overlappingone over the other and changed in position relative to each other in alength direction and/or width direction thereof, and the two rectangularresin foams are provided with plate-shaped vacuum heat-insulationmaterials encapsulated therein, respectively.
 4. The heat insulationpanel according to claim 1, wherein the board-shaped resin foam iscomposed of two rectangular resin foams of different lengths and/orwidths overlapping one over the other with centerlines thereof coincidedwith each other, and larger one of the two rectangular resin foams isprovided with the plate-shaped vacuum heat-insulation materialencapsulated therein.
 5. A heat insulation structure comprising aplurality of heat insulation panels as defined in claim 1, wherein theheat insulation panels are arranged in abutment with each other atproximal edges thereof such that plate-shaped vacuum heat-insulationmaterials thereof overlap with each other at proximal end portionsthereof as viewed in a thickness direction of the heat insulationpanels.